An explosion was reported at Port Authority in New York City on Dec. 11, 2017.
Credit: Bryan R. Smith/Getty Images

An explosion was reported in a subway passage at the Port Authority in New York City during Monday's morning commute. Four injuries have been reported.

Police said the explosion just before 7:30 a.m. was caused by a small pipe bomb, ABC News reported. One suspect is in custody.

Port Authority is a major transportation hub in the city, at 42nd Street and 8th Avenue, connecting train and bus commuters.

Police evacuated people on the A, C, and E subway lines, which all run on the same track through 42nd Street. Additional subway delays are possible as police respond in the area, and most of the subway lines in the area — 1, 2, 3, 7, A, C, E, N, Q, R, W — are bypassing 42nd street, according to the MTA, amNewYork reported.

The male suspect, who was injured, is in custody, according to the NY Daily News.

This is a developing story.